1. Field of the Invention
The present invention relates to an image-processing system configured to control processing for printing an image according to changing information and also to a control method, a program, and a storage medium therefor.
2. Description of the Related Art
A conventional system includes a charging apparatus, such as a coin vendor or a card vendor, and an image-forming apparatus connected to each other, and manages charging information related to print processing (copying or printing). Such a conventional system is used in the case of providing a printing service to an indefinite number of users at a store (for example, a convenience store) or in an office to manage the number of consumed printing paper sheets for each division.
More specifically, a user who desires to use a copy service, for example, prepays a fee for the desired copy processing via a coin vendor or using a prepaid card or a credit card. After setting various copy parameters (parameters for the number of documents, the number of copies, the paper size, and the color mode (monochromatic/color)), the user instructs printing. Then, the fee corresponding to the amount of prints to be performed according to the set parameters is deducted from the paid fee, and then the print operation starts. If the remaining fee is short of the amount to be charged for the desired printing, the print processing does not start.
Meanwhile, the remaining amount of fee may become short of the required charge during the print processing instructed by a user. For example, in the case where a user has instructed print processing for five pages when the user paid a fee for printing only three pages, the instructed print processing is suspended when the shortage of the paid fee is detected after performing the print processing for three pages. In this regard, Japanese Patent Application Laid-Open No. 2001-305919 discusses the following method for avoiding performing print processing for pages whose fee is yet to be paid or outputting an incompletely-printed product.
The method discussed in Japanese Patent Application Laid-Open No. 2001-305919 prevents, in the case of reading an image on one side of a document and forming an image on both sides of print paper, a number of print products from being output exceeding the number of products for which the fee has been paid, by performing print processing after checking the remaining amount of the paid fee before starting every print paper-feed operation. The method discussed in Japanese Patent Application Laid-Open No. 2001-305919 suspends the feeding of the print paper when the remaining amount of the paid fee is smaller than the charge for printing an image on both sides of the print paper and thus an image can be formed on only one side of the print paper and if an image to be formed on the other side of the print paper still remains.
However, the method discussed in Japanese Patent Application Laid-Open No. 2001-305919 has the following problems. That is, with the method discussed in Japanese Patent Application Laid-Open No. 2001-305919, which checks the remaining amount of the paid fee before starting a print paper-feed operation and starts a print paper-feed operation after determining that the remaining amount of the paid fee is large enough to perform the instructed printing, the print processing cannot be performed at a high speed and thus the printing efficiency may degrade. In particular, in the case where an image-forming function for actually performing print processing and a charging information managing function are provided to respective different apparatuses and where the apparatuses are connected to each other to perform data communication for performing the instructed print processing, a long time may be required to check for the remaining amount of the paid fee. Thus, the printing efficiency may degrade.
On the other hand, print processing can be performed at a speed higher than that in the case of the above-described method by starting a print paper-feed operation and a print operation in parallel to checking the remaining amount of the paid fee, instead of starting a print paper-feed operation after checking the remaining amount of the paid fee. With such a method of starting a print paper-feed operation or a print operation before determining that the remaining amount of the paid fee is large enough to start the instructed processing, the printing efficiency can improve because the length of time required for checking the remaining amount of the paid fee can be appropriately reduced.
However, with such a conventional method, when it is detected that the remaining amount of the paid fee is not large enough to complete the instructed processing and when the image-forming apparatus has received an instruction from the charging apparatus for suspending the current print processing, the image-forming apparatus cannot suspend the already-started print paper-feed operation or print operation. In this case, the fee for the print processing that has been already performed exceeding the already-paid fee cannot be appropriately charged.
As described above, the two conventional methods have advantages and drawbacks. Accordingly, in the case of using only one of the two methods, the print efficiency may degrade or the management of charging may not be appropriately performed.